Arkansas: Salida to Portland

Evolution of the network

Gage flow trend & changepoints

Of the 22 gages with enough record, 3 are trending down and 1 up, and 5 carry a detected shift. The clearest is BADGER CREEK, UPPER STATION, NEAR HOWARD, CO, -133.1 points of its long-term median per decade over 23 years (p=0.0018). The other 15 show no clear signal either way.

15 other gage(s) show no significant trend or changepoint (not shown).

How the measurement network itself changed

This basin was not always measured the way it is today — the API-era record is dense and recent, the early record sparse. 15 gage(s) and 278 structure(s) report in 2026, but structure reporting only reached half its modern level around ~1970. Every historical claim below is checked against this: long-term shifts that co-move with the growth of the network carry an explicit measurement-evolution caution, and abandonment screens whose idleness begins before the modern reporting era are flagged †.

Mass-balance (network closure) trend

Structure divrec-history backfill coverage as of the last check: 1% of 2970 schematic-relevant structures. 0 year(s) clear the 30% coverage gate so far -- the trend activates automatically once qualifying years span a full decade. No action needed; the nightly backfill keeps extending the record.

Reach gain/loss shifts (1950–2026)

Mass-balance kinks computed for every summer month back to 1950 (1052 reach-snapshots) — which reaches gain or lose water, and how that has shifted across decades. Each shift is cross-checked against the observation record above: as more diversions became metered, "unaccounted" water shrinks mechanically, which can masquerade as a hydrologic shift.

• BEAVER CREEK NEAR PORTLAND, CO.: reach shifted from -812 cfs to -1599 cfs summer mean (more losing, p=0.012, 18 yr) [sedimentary plains/foothills: moderate groundwater connectivity -- gain/loss shifts can be real aquifer response; corroborate with nearby well records] [2 alluvial wells within 2 mi of the gage; pooled water table +1.9 ft (1973–1994, no_trend)]
• BADGER CREEK, LOWER STATION, NEAR HOWARD, CO.: reach shifted from +9 cfs to +8 cfs summer mean (more losing, p=0.034, 18 yr) [sedimentary plains/foothills: moderate groundwater connectivity -- gain/loss shifts can be real aquifer response; corroborate with nearby well records] [2 alluvial wells within 2 mi of the gage; pooled water table -3.2 ft (1980–1990, no_trend)]

Groundwater now has its own tab: 187 monitored well(s), water-table trends, stream corridors, and the advisory depletion screen.

Reservoirs now has its own tab: 28 reservoir(s), end-of-year storage back to 1950, click-to-chart histories.

Cross-gage pattern fingerprint

Over the 34-year window with full coverage (1993–2026), the dominant shared pattern across 3 gage(s) explains 82% of year-to-year variance (almost certainly a basin-wide climate/snowpack driver).

All gages in this window move with the shared pattern -- no localized outlier.

1,346 water-level measurements across 187 monitored well(s) — 128 alluvial, 0 bedrock — plus 14 administered well(s) reporting metered pumping.

Well map

3D aquifer x-ray

Every aquifer unit as its own head surface, animated through time.

Water-table trends

Of 14 well(s) with enough record for a trend test: 3 declining, 3 rising.

Stream corridors — the surface connection

Where a reach's gain or loss has shifted, the wells within two miles of its anchoring gage and what their water table did over the same era.

BEAVER CREEK NEAR PORTLAND, CO.: 2 alluvial well(s) nearby; pooled water table +1.9 ft (1973–1994, no_trend, p=0.0501)

BADGER CREEK, LOWER STATION, NEAR HOWARD, CO.: 2 alluvial well(s) nearby; pooled water table -3.2 ft (1980–1990, no_trend, p=0.2758). Glover screen: 0.0 cfs of nearby metered alluvial pumping → est. lagged depletion 0.0–0.0 cfs (uncalibrated T/S ranges; flagged for SPDSS calibration, AWAS cross-check, and expert review — DWR's AWAS is the authority).

Wells labeled by administrative world before anything else is said about them: tributary alluvium participates in the priority system; designated-basin and Denver Basin bedrock aquifers are governed differently and are excluded from stream-connection reasoning. Read bedrock declines differently too: deep bedrock aquifers recharge negligibly on human timescales, so a falling bedrock level is storage mining — effectively permanent — not a drought response that a wet year undoes. All screens advisory.

28 reservoir(s) with 50,282 storage measurement(s), 1950–2026. Basin storage as of 2025-10-31 (the record's own end — reservoir records publish ~annually): 12,167 AF across 24 reservoir(s).

Reservoir map — how full is each vessel?

Basin storage, end of each water year

End-of-water-year totals; per-year reservoir counts shown because reporting coverage varies -- a total is only comparable to years with similar counts.

Largest reservoirs on record

Click a reservoir to chart its full storage history.

If a call were placed at a given seniority, which structures in this basin would be out of priority, and how much of their decreed rate would be curtailed? Computed from this basin's cached decrees.

Pick a calling right

Real decrees from this basin, ordered by administration number — that is, by actual seniority. The years will look out of order, and that is correct: an administration number encodes the adjudication date as well as the appropriation date, so a right appropriated in 1970 can be administered ahead of one from 1950. A senior call curtails almost everything; a junior one curtails almost nothing.